1. Field of the Invention
This invention relates to gate valves used in machine shops that serve to control the flow of suction in collecting sawdust, mill filings and the like and more particularly to an electric gate valve and accompanying system allowing the efficient operation of vacuum collection of dust and filings.
2. Description of the Related Art
In machine shops, woodworking shops, and the like, work pieces are milled, lathed, drilled, formed, etc. to achieve the ends of the craft. In altering the structure of the workpiece, dust, filings and/or tailings are created. For example, when sawing a piece of wood, sawdust will collect adjacent the area of the saw blade. Likewise, for lathing or milling processes, shavings or tailings from the metal workpiece about or below the cutting blade.
The sawdust and/or metal shavings that collect in the workshop can become dangerous. The dust or microfine metal particles may become airborne and inhaled deeply into the lungs of persons in the general vicinity. Additionally, thick suspensions of dust become fire or explosion hazards as an explosion or fire may occur if the dust comes into contact with a spark of flame. Consequently, it is of great interest both to the proprietor and to the persons working in the shop to minimize the hazards arising from collection and suspension of dust and the like. Likewise, governmental regulations may impose similar safety requirements.
Prior attempts to eliminate sawdust, metal shavings, and the like from the machine shop work area have used a centralized vacuum system where a central vacuum motor pulls a vacuum through a series of ducts. The end of the ducts are open adjacent the machine areas where dust or wood collect. The dust then travels through the ductwork to a collection or storage bin that is emptied on a periodic basis. Currently, in furtherance of the art, gates controlling the flow of air through the ductwork may be used so that a vacuum or suction is only pulled in areas where actual work is being done. This eliminates the energy waste associated with the vacuuming of otherwise clean and dust free areas. It also reduces the load the vacuum has to pull.
Currently, blast gates are known in the art and may be controlled hydraulically or through air (as an alternative fluid). These gates are generally expensive and use a number of moving parts. Additionally, such blast gates and their hydraulic lines may be difficult to install, often requiring a professional. Such expense and difficulty may prevent their installation in smaller workshop areas where the initial cost may outstrip the monies available to pay for such a safety system.
Automatic control of such blast gates is preferred to manual operation as it is most the most efficient and convenient. While the preferred placement of blast gates is as close to the dust-creating machinery as possible, automatic also blast gates enable the spacing of the blast gates away from a flexible end of the duct so that it may have as much freedom as possible to operate, flexing under manual control to collect available dust, etc. or to be easily fixed in an advantageous dust-collecting position relative to a machine. Additionally, with manual gates, the operator must manually operate each of the gates for each of the machines. Gates that are left open when the associated machine is not being used are noisy and waste energy. Without the use of blast gates, the central dust collector must be much larger as the effective vacuum it must pull must match that necessary for every machine and every open duct.
Consequently, it is to some advantage to provide an inexpensive vacuum system using a simple and effective blast gate that is self-cleaning and provides automatic response to the operation of a machine for which dust needs collection. Such a system may use a simple, easy to manufacture, and easy to maintain blast gate that is signalled by a central processor. The central processor may receive signals from a sensor that detects whether or not a machine associated with the sensor is in operation and therefore whether or not dust should be collected at that location.
The invention described in the foregoing description and accompanying claim remedies many of the drawbacks presently exhibited by machine shop dust collection systems and does so in an inexpensive and highly-effective manner.